title: Simultaneous screening analysis of 3-methyl-quinoxaline-2-carboxylic acid and quinoxaline-2-carboxylic acid residues in edible animal tissues by a competitive indirect immunoassay.
abstract: Immunoassays contribute greatly to food safety. Yet there are no reported immunoassays that simultaneously detect MQCA and QCA, the marker residues for olaquindox and carbadox, respectively. Here, a broad-specificity mAb was successfully produced, and the mAb showed good cross-reactivity with both MQCA and QCA, having IC50 values in buffer of 4.8 and 9.6 ng/mL, respectively. The calibration curves ranged from 0.3 to 81 μg/kg. The average recoveries ranged from 76% to 108% at different spiked levels (2, 4, and 8 μg/kg for MQCA; and 4, 10, and 20 μg/kg for QCA), and the intra-/interday coefficients of variation were 4.2-13.3%. The limits of detection of MQCA and QCA in chicken, fish, pork, and shrimp were 1.76, 1.32, 1.90, and 1.18 μg/kg, respectively. This method was verified by LC-MS/MS, with a correlation coefficient above 0.98. The immunoassay was rapid and reliable for simultaneous screening analysis of MQCA and QCA residues.
authors.affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University , Beijing 100094, China.
authors.forename: Wenxiao
authors.initials: W
authors.lastname: Jiang
authors.forename: Ross C
authors.initials: RC
authors.lastname: Beier
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Yongning
authors.initials: Y
authors.lastname: Wu
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002645:Chickens; D004350:Drug Residues / Q000032:analysis*; D005399:Fishes; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000379:methods*; D008460:Meat / Q000032:analysis*; D011810:Quinoxalines / Q000032:analysis*; D017747:Seafood / Q000032:analysis*; D013552:Swine
chemical_list: C581287:3-methylquinoxaline-2-carboxylic acid; D000900:Anti-Bacterial Agents; D011810:Quinoxalines; C042218:quinoxaline-2-carboxylic acid